Vol15 No.4: 752-764
【Title】A terrain openness index for the extraction of karst Fenglin and Fengcong landform units from DEMs
【Author】MENG Xin1,2,3; XIONG Li-yang1,2,3*; YANG Xian-wu1,2,3; YANG Bi-sheng4;TANG Guo-an1,2,3
【Addresses】1 Key laboratory of Virtual Geographic Environment, Ministry of Education, Nanjing Normal University, Nanjing 210023, China; 2 State Key Laboratory Cultivation Base of Geographical Environment Evolution (Jiangsu Province), Nanjing 210023, China; 3 Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China; 4 State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, 430079, China
【Citation】Meng X, Xiong LY, Yang XW, et al. (2018) A terrain openness index for the extraction of karst Fenglin and Fengcong landform units from DEMs. Journal of Mountain Science 15(4). https://doi.org/10.1007/s11629-017-4742-z
【Abstract】The Fenglin and Fengcong landform units are considered to be an important representation for defining the degree of development of Karst landforms. However, these terrain features have been proven difficult to delineate and extract automatically because of their complex morphology. In this paper, a new method for identifying the Fenglin and Fengcong landform units is proposed. This method consists of two steps: (1) terrain openness calculation and (2) toe line extraction. The proposed method is applied and validated in the Karst case area of Guilin by using ASTER GDEM with one arc-second resolution. The openness of both the positive and negative terrain and a threshold were used to extract toe lines for segmenting depressions and pinnacles in Fenglin and Fengcong landforms. A comparison between the extracted Fenglin and Fengcong landform units and their real units from high resolution images was carried out to evaluate the capability of the proposed method. Results show the proposed method can effectively extract the Fenglin and Fengcong landform units, and has an overall accuracy of 93.28%. The proposed method is simple and easy to implement and is expected to play an important role in the automatic extraction of similar landform units in the Karst area.
【Keywords】DEM; Karst landform; Fenglin and Fengcong landform; Terrain openness; Landform units